The device costs $99 and it attaches to their regular collar. It's pretty small, nothing like those dog trackers with the huge antenna's. It has a monthly fee associated with it because it uses AT&T cell service to track your dog when it ventures outside of your home wifi signal. I bought the 2 year plan and it was something like $6.95/month paid in advance, so for two years I paid about $275 including the device.
You have to take the device off and recharge it every so often, today is the first full day of wearing it and so far the app shows it at about 90% battery, so I'm guessing every 5 days or so.
It's really a neat device, it shows distance traveled, it shows the map of where they went and where they are now. I like it because I camp and want to know if the little fart decides to wander that I can find him. Also He has escaped from the fenced in yard a couple of times and while he came back home if he gets out I want to know where to find him.